This invention relates to a plough for winning material in a longwall working, and to a mineral mining installation incorporating such a plough.
A conventional mineral mining installation consists of a scraper chain conveyor positioned alongside a longwall face, and a plough driven along a guide at the face-side of the conveyor by an "endless" chain. The chain may be accommodated in guide channels defined within the guide. Alternatively, the chain may be accommodated in channels in a chain guide positioned at the goaf-side of the conveyor, in which case the plough is attached to the chain by means of a sword plate which passes underneath the conveyor. In either case, the chain passes over sprockets mounted on the drive frames at the two ends of the conveyor. At least one of these plough driven chain end sprockets is provided with a drive unit.
The disadvantage of these conventional installations is that it is not possible for the plough to mine material from the entire length of a longwall face. It is necessary, therefore, to mine material from the longwall face ends (the so-called "stable-holes") either manually or by means of special stable-hole ploughs, which considerably increase the cost of the installation. These stable-holes actually need to be cut away to a greater depth than that by which the face itself is worked, in order to accommodate the heavy and bulky drive units for the main plough and the conveyor.
A swordless plough is known which can win material over the entire length of a longwall face without the aid of a stable-hole plough. The drive chain for this plough is attached to the central region of the plough body, so that cutters mounted at the two ends of the plough body can win material up to the sprocket wheels mounted on the drive frames at the two ends of the associated conveyor. Unfortunately, the drive unit(s) for this type of plough cannot be attached to the side plate(s) of the drive frame(s). This results in the plough drive unit(s) being attached to the free end(s) of the drive frame(s) which results in added congestion to the already crowded longwall working/roadway interface(s). Moreover, the plough guide must be angled away from the conveyor in the end regions so as to permit the plough drive chain to pass from the end sprockets to the channels in the face-side guide. (see DE OS No. 2 704 809).
The aim of the invention is to provide a mineral mining installation for winning material in a longwall working which enables the entire length of the longwall to be mined by a single plough, without the need for additional plant or expense to win material in the stable-hole regions, and which does not suffer from the disadvantages of the known installations.